Prescription Weight Loss / Diet Pills: What Are the Options?
Medically reviewed on Sep 26, 2016 by L. Anderson, PharmD.
Prescription weight loss pills, also called anti-obesity drugs or “diet pills”, are sometimes prescribed to a patient as an additional tool in the treatment for weight loss. Additional tools to medication treatment usually include a plan for lower fat and calorie foods, as well as a regular exercise program.
- Patients who are overweight or obese with any health condition should consult with their physician prior to beginning a weight loss or exercise program. To assess your health risk based on weight, calculate your body mass index (BMI) here.
There are very few proven choices in over-the-counter (OTC) or nonprescription medications for effective weight loss. One agent that is available without a prescription is Alli (orlistat), a lower-dose version of the prescription drug Xenical. Many people who are trying to lose weight may attempt to use dietary supplements or herbal medications, but many of these products have not been adequately studied for effectiveness or safety.
Herbal or dietary supplements have not been approved by the U.S. Food and Drug Administration (FDA) for weight loss. Check with a healthcare provider for advice on using herbal or dietary supplements for weight loss.
Weight Loss Drugs
Prescription weight loss drugs may be an option for patients who have serious health risks, such as high blood pressure, type 2 diabetes, or high cholesterol and cannot control their weight with diet and exercise alone. Weight loss drugs should not be used as a substitute for healthful eating and a regular exercise program.
- Over one year, patients using weight loss drugs may lose roughly 5 to 10 percent of their initial weight when used as part of a diet and exercise plan.
Most weight loss drugs that suppress the appetite are known as anorexiants. Some weight loss drugs contain stimulant medication that are classified as controlled substances by the Drug Enforcement Agency (DEA). In 2012, the FDA approved the first two new weight loss drugs in over a decade - Belviq and Qsymia. Since that time, several more new weight loss medications have been approved, including Contrave, Saxenda, and Belviq XR.
Common "Diet Pills" or Weight Loss Drugs
|Brand Name||Generic Name||Description||Controlled Substance?|
|Phentermine||Appetite suppressant; anorectic||Yes, DEA schedule IV|
|Alli||Orlistat||Lipase inhibitor; inhibits fat absorption in the intestine||No, available over-the-counter (OTC)|
|Belviq, Belviq XR||Lorcaserin||Selective serotonin 2C receptor agonist; promotes a feeling of fullness or satiety||Yes, DEA schedule IV|
|Bontril PDM, Bontril SR||Phendimetrazine||Appetite suppressant; anorectic||Yes, DEA schedule III|
|Desoxyn||Methamphetamine||Appetite suppressant; use cautiously if prescribed for weight loss due to high potential for abuse, illegal distribution||Yes, DEA schedule II|
|Didrex||Benzphetamine||Appetite suppressant; anorectic||Yes, DEA schedule III|
|Diethylpropion||Diethylpropion||Appetite suppressant; anorectic||Yes, DEA schedule IV|
|Meridia||Sibutramine||Anorectic; withdrawn from US market in 2010 due to increased heart risk.||Not available|
|Qsymia||Phentermine and topiramate extended-release capsules.||Combination appetite suppressant-anorectic; exact action of topiramate on weight loss is not known||Yes, DEA schedule IV|
|Suprenza||Phentermine||Appetite suppressant; anorectic||Yes, DEA schedule IV|
|Xenical||Orlistat||Lipase inhibitor; prescription form of Alli (OTC); higher dose than Alli; inhibits fat absorption in the intestine||No|
|Contrave||Bupropion hydrochloride-naltrexone hydrochloride||Increases metabolism, suppresses appetite, affects central reward center (proposed mechanism)||No|
|Saxenda||Liraglutide||GLP-1 may regulate areas of brain involved in appetite (proposed mechanism)||No|
How Effective Are Weight Loss Drugs?
Weight loss drugs may not work for everyone. It is usually recommended that one to two pounds of weight can be safely lost per week.
- Weight loss drugs typically result in a 5 to 10 percent weight loss over a 12-month period when used as part of a diet and exercise plan.
For a patient weighing 200 pounds, this would translate into losing about 10 to 20 pounds over one year, which would fall within the safe guidelines for weight loss. While this amount of weight loss seems small, it may be enough to help lower blood pressure or have a positive effect on blood sugar.
Who Are Candidates for Weight Loss Drugs?
Generally, most overweight people should initially try to lose weight using diet and exercise. Prescription diet pills are used in more severe circumstances, when weight loss has not been successful and the patient has important health risks associated with being overweight or obese. However, prescription weight loss drugs should be used in addition to diet and exercise.
Weight loss drugs should not be used during pregnancy. All weight loss drugs fall under pregnancy category X and are contraindicated in pregnancy. Weight loss offers no potential benefit and may result in fetal harm during pregnancy. A certain amount of additional weight gain, and no weight loss, is currently recommended for all pregnant women, including those women already overweight or obese.
Most prescription weight loss drugs note in the package labeling that a person should meet certain requirements, such as a specified body mass index (BMI) and/or have a serious medical risk before using the drug. Weight loss drugs are usually indicated for obese patients with an initial body mass index (BMI) > 30 kg/m2 or overweight patients with a BMI > 27 kg/m2 in the presence of other risk factors (eg, high blood pressure, type 2 diabetes, high cholesterol). Example of serious medical risks include:
- Childhood Obesity: Is a U.S. Epidemic Improving?
- How to Calculate Your Body Mass Index (BMI)
- Side Effects of Weight Loss Drugs (Diet Pills)
- Weight Loss
- Weight Loss Surgery
- Which Prescription Drugs Cause Weight Gain?
- Centers for Disease Control and Prevention. Overweight and Obesity. Accessed 9/26/2016. http://www.cdc.gov/obesity/adult/defining.html
- Drugs.com. Obesity. Accessed 9/26/2016. https://www.drugs.com/health-guide/obesity.html
- Centers for Disease Control and Prevention (CDC). Assessing Your Weight: About Adult BMI. Accessed 9/26/2016. http://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/index.html
- Department of Health and Human Services. NIH. National Heart, Lung and Blood Institute. Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults. Accessed 9/26/2016. http://www.ncbi.nlm.nih.gov/books/NBK2003/